TET_MESH_TO_GMSH
Convert Tet Mesh Files to GMSH MSH Format

TET_MESH_TO_GMSH is a C program which converts a pair of files defining a tetrahedral mesh into an equivalent file using the Gmsh msh format.

In particular, TET_MESH_TO_GMSH reads a node coordinate file listing the coordinates of a set of 3D points, and an element file list sets of 4, 10 or 20 nodes that form tetrahedral elements. It creates a single equivalent file in the Gmsh msh format.

Usage:

tet_mesh_to_gmsh prefix

• 'prefix'_nodes.txt contains the node definitions;
• 'prefix'_elements.txt contains the element definitions;
• 'prefix'.msh will be the Gmsh msh file created by the program.

Licensing:

The computer code and data files made available on this web page are distributed under the GNU LGPL license.

Languages:

TET_MESH_TO_GMSH is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version.

Related Programs:

DOLFIN-CONVERT, a Python program which can convert mesh file from Gmsh, MEDIT, METIS or SCOTCH format to an XML format suitable for use by DOLFIN or FENICS, by Anders Logg.

GMSH, examples which illustrate the use of the Gmsh program, a 3D mesh generator for the finite element method (FEM).

MSH, a data directory of examples of MSH files, the native 3D mesh format used by Gmsh.

TET_MESH, a C++ library which includes a variety of routines for working with tetrahedral meshes.

TET_MESH_L2Q, a C++ program which takes a 4-node tet mesh and makes a 10-node tet mesh.

TET_MESH_ORDER4, a dataset directory which contains a description and examples of a tet mesh using order 4 elements.

TET_MESH_ORDER10, a dataset directory which contains a description and examples of a tet mesh using order 10 elements.

TET_MESH_ORDER20, a dataset directory which contains examples of order 20 tetrahedral meshes.

TET_MESH_Q2L, a C++ program which takes a 10-node tet mesh and makes a 4-node tet mesh.

TET_MESH_TO_XML, a C program which reads information defining a tet mesh, namely a file of node coordinates and a file of elements defined by node in

TRIANGULATION_TO_GMSH, a C program which converts the data defining a triangulation into an equivalent Gmsh msh file.

Reference:

1. Christophe Geuzaine, Jean-Francois Remacle,
   Gmsh: a three-dimensional finite element mesh generator with built-in pre- and post-processing facilities,
   International Journal for Numerical Methods in Engineering,
   Volume 79, Number 11, pages 1309-1331, 2009.

Source Code:

• tet_mesh_to_gmsh.c, the source code.
• tet_mesh_to_gmsh.sh, commands to compile the source code.

Examples and Tests:

• mesh_nodes.txt, the nodes for the 4-node tet mesh.
• mesh_elements.txt, the elements for the 4-node tet mesh.
• mesh.msh, the Gmsh msh file version of the data.

List of Routines:

• MAIN is the main program for TET_MESH_TO_GMSH.
• CH_CAP capitalizes a single character.
• CH_EQI is true if two characters are equal, disregarding case.
• CH_TO_DIGIT returns the value of a base 10 digit.
• FILE_COLUMN_COUNT counts the columns in the first line of a file.
• FILE_ROW_COUNT counts the number of row records in a file.
• GMSH_WRITE writes the triangulation data as a Gmsh mesh file.
• I4_MAX returns the maximum of two I4's.
• I4_MIN returns the minimum of two I4's.
• I4MAT_DATA_READ reads data from an I4MAT file.
• I4MAT_HEADER_READ reads the header from an I4MAT file.
• I4MAT_TRANSPOSE_PRINT_SOME prints some of an I4MAT, transposed.
• R8MAT_DATA_READ reads the data from an R8MAT file.
• R8MAT_HEADER_READ reads the header from an R8MAT file.
• R8MAT_TRANSPOSE_PRINT_SOME prints some of an R8MAT, transposed.
• S_LEN_TRIM returns the length of a string to the last nonblank.
• S_TO_I4 reads an I4 from a string.
• S_TO_I4VEC reads an I4VEC from a string.
• S_TO_R8 reads an R8 from a string.
• S_TO_R8VEC reads an R8VEC from a string.
• S_WORD_COUNT counts the number of "words" in a string.
• TET_MESH_BASE_ONE ensures that the element definition is 1-based.
• TIMESTAMP prints the current YMDHMS date as a time stamp.

You can go up one level to the C source codes.